If you haven't already found a solution, you should be able to find an example at this link: https://github.com/arquillian/arquillian-container-jbossas
These are the sources for the different JBoss container but in the tests you can find an example of test case and in the pom.xml an example of configuration.
In the managed case:
The test: https://github.com/arquillian/arquillian-container-jbossas/blob/master/jbossas-managed-4.2/src/test/java/org/jboss/arquillian/container/jbossas/managed_4_2/JBossASIntegrationEarTestCase.java
I hope this can be useful, sorry for the lack of doc I'll try to update it soon (if no-one else does ).